At 15, he became a professional musician and enjoyed many years as a recording and touring artist with bands including Robyn Hitchcock,[2] the Television Personalities[2] and the Irish group Light a Big Fire. Mark played drums on Light a Big Fire's second album.[3] As a session musician, he recorded albums for many groups throughout Europe,[citation needed] and eventually moved to the United States.

Sheppard was invited to audition for the American production of the play Cock and Bull Story (directed by Midnight Express author Billy Hayes), for which he won numerous awards, including the 1992 L.A. Drama Critics' Circle award and the LA Weekly and Dramalogue awards.

Mark Sheppard directed his father W. Morgan Sheppard in the film Room 101 and co-stars with him in the psychological thriller Nether World, which the younger Sheppard also co-produced. His father also played the older version of his son's character in the afforementioned Doctor Who episodes.

Three times Sheppard has been cast with his father as the same character, each playing the character at different ages. "Canton Everett Delaware III" in the Doctor Who episode "The Impossible Astronaut",[1]War criminal Mercin Jarek a.k.a. "Mr. Pain" in the NCIS episode "Broken Bird" playing the younger version of his father's character, and "Captain Nemo" in the 2010 film Mysterious Island, which Mark Sheppard also directed.

^ ab"Hayes Moves in New Direction". Daily News of Los Angeles. 3 April 1992. They are played by Trevor Goddard, a former pro boxer, and Mark Sheppard, a drummer who has performed with the Barracudas, Robyn Hitchcock and the TV Personalities.